1. Field of the Invention
This invention relates to computer networks and, more particularly, to protecting data within computer networks.
2. Description of the Related Art
In the enterprise computing environment, it has become common for client computers to be dynamically connected to the enterprise network through a variety of connection types. Furthermore, the increasing use of mobile devices such as laptop computers has meant that the method of connection to the enterprise network may change frequently as the mobile user travels from place to place. For example, each mobile computer may connect to a network via modem, wireless local area network (LAN), direct wired LAN, wireless connection through a wide area network (WAN) or direct cable through a WAN, among other methods dependent upon the available connection options at any particular location. While it is generally useful to be able to use a variety of connection types, the capabilities of each connection vary from one type to another. For example, modem connections are generally slower than wireless connections, which may be slower than directly cabled connections. In addition, direct LAN connections may be faster than connections that require data to be transferred across a WAN.
Because of the differing capabilities of various connection types, it is generally desirable for software applications to be able to determine if and when a network connection changes. There are a variety of ways to determine the characteristics of a network connection. For example, Microsoft's Windows® operating system provides some standard network API calls to the application programmer. In particular, a call to RasConnectionNotification( ) notifies the caller when the remote access service (RAS) connection state changes. Also, a call to NotifyAddrChange( ) notifies the caller when the IP address changes for any reason, such as disabling of the network interface card, unplugging a cable, establishment of a dial-up connection, etc. In addition, an application may request information about a connection by calling InternetGetConnectedState( ) which returns the current connection type (modem, LAN, not connected, etc.) Other operating systems may provide similar capabilities.
In addition to the above considerations, it is generally desirable for enterprises to protect the data that resides on mobile computing devices via some type of backup mechanism. However, changes to the connection type by mobile users tend to complicate any backup mechanism. For instance, a backup mechanism may attempt to backup data from a mobile computer each time it is connected to the enterprise network, regardless of connection type. However, if the connection type is slow, such as via a modem, a user who is attempting to access e-mail or browse the internet may be frustrated as the available bandwidth is consumed by backup data transfers. Depending on a number of factors, it may not be necessary to require the same backup policy for every user regardless of connection type. For example, an enterprise data protection strategy may prefer to adjust the frequency of data backups according to the identity of the user, the type of connection, and/or the bandwidth of the connection. In addition, it may be desirable to determine whether to backup individual files based on the combination of file size and connection type. Therefore, backup policies that account for these issues are desired.